Lubricant



Patented Oct. 7, 1941 LUBRICANT John C. Zimmer, Hillside, .N. J.,assignor to Standard 011 Development Company, a corporation of DelawareNo Drawing. Application April 7, 1938, Serial No. 200,681

10 Claims.

The present invention relates to the art of lubrication and moreparticularly to lubricants containing fillers, which lubricants are usedparticularly for metal working operations such as stamping, drawing,forging and the like. The invention will be fully understood from thefollowing description.

Lubricants for metal working processes such as forging, stamping,drawing and the like are generally of the type containing inert fillers.These fillers are of the type of talc, chalk, calcium carbonate and thelike and serve the purpose of preventing metal-to-metal contact underhigh pressures which are encountered in the said processes.

It has been found that much better results can be obtained by'us ing asfillers certain inof the fatty. material to soap. Where 20 to 35 partsby weight of the fat are employed, 30 to 50 parts of mineral oil wouldbe used with from 10 to 40 parts'of water.

organic salts which possess extreme pressure or anti-weld properties.The particular salts contemplated herein are particularly thephosphates, sulfides and borates of polyvalent metals, especially thoseof the second group of the Periodic System, especially calcium, zinc andlead salts, and also similar salts of tin. Whilev any of the above saltswhich are substantially insoluble both in water and oil may be used, itis preferred to use the salts of zinc, calcium and lead.

It has been found that the particular salts mentioned hereinaboveperform the various functions which were perform'edby the previous inertfillers, but at the same time they are found to endow the lubricatingcompound with the ability to withstand considerably higher pressureswithout metal failure, seizure or scoring. Inaddition they appreciablyreduce the friction. facilitate the flow of metal into the die recessesand thus reduce the power requirements for the fabricating operations.They likewise give the work an attractive, burnished appearance which isnot obtained with the well known inert fillers, and reduce the frequencyof splits, cracks, or other blemishes in the drawing or stamplngs.

In making up the present compounds, the ordinary procedures can be used.For example, a fat such as tallow, palm oil, degras, or fatty oil orfatty acids of vegetable, animal or mineral origin is first saponifledwith an alkaline solution such as caustic soda or potash or with lime,and thereafter additional water and oil are worked into the compound soas to make up an emulsion of a thick, pasty type. It is found desirablenot" to completely esterify the fatty substances and the amount ofalkali added is preferably only sumcient to convert '75 to 80% The oilused is a lubricating oil and distillates or residuals may be used,depending on the particular use. The compound made up as before is athick, white to dark brown paste having a consistency ranging frommayonnaise to heavy greases. ually stirred in while heating gently. Theamount of the filler may vary from about 2 to 40% of the mixture,depending to some extent on the type of the particular filler added andthe use for which it is employed. Generally speaking, however, from 5 to10% is suihcient for most purposes.

The above mentioned compounds may be used as such in the case of heavydrawing or stamping. The paste is spread on the work in a thin layer andafter the operation contemplated has been performed, the compound may bescraped off and recovered for'reuse. It is also possible,

- in the case of light drawing and stamping, to

use a fluid mixture which is obtained by diluting the compound as madeabove with a relatively large amount of water. In this condition thematerial is'a free flowing emulsion.

While the borates and sulfides may be used as indicated above, it ispreferred to use phosphate compounds and zinc and calcium. acidphosphates are the most useful.

The following example is given to illustrate the method by which thecompound is made and to demonstrate its superiority over drawingcompounds of the present type.

Example I mixture are then added 2, 5 and 10% by weight of zincphosphate, 5 and 10% by weight of calcium acid phosphate and 10 and 20%by. weight of calcium carbonate. The primary compound without theaddition of filler and the same to which the various fillers had beenadded were then tested for their film strength on an Almen The filler isnow added and is gradmachine, under strictly comparable conditions.

In the table below, the composition 01' the compound is given togetherwith the number of weights it was able to carry on the Almen machine:

Almen data on drawing compounds Almen test, No. of wts.

Percent filling material added carried HM HHHHH u-wmmGcuano-MA In theabove test it will be noted that the compound without fillers carriesonly 4 weights. The improved compounds, however, containing zinc andcalcium acid phosphates respectively were very efiective. 2% oizincphosphate,-for example, were able to carry 13 weights whereas thecompound containing 5% of ordinary calcium carbonate could only carry 6weights, and doubling or quadrupling the amount of the filler onlyraised the load carried to 11 weights. It also should be noted thatthecompounds containing 5 and of the said phosphates did not fail in theAlmen test. These compounds carried the full 15 weights for which themachine is designed and the test does not indicate pressures at whichsuch compounds actually would fail.

The present invention is not to be limited to any theory of the actionof the improved filling materials nor to any particular filling compoundor ratio of ingredients, but only to the following claims in which it isdesired to claim all novelty inherent in the invention.

I claim:

1. An improved lubricant for metal working processes comprising anaqueous emulsion of a mineral lubricating oil to which has been added afiller consisting of a polyvalent metal salt 01' an 2 azuaaoe acidselected from the class consisting of phosphoric, boric andhydrosulfuric acids, which salt is substantially insoluble both in oiland water.

2. A lubricant according to claim 1 in which the inorganic salt is asalt of a metal of the second group of th Periodic Table.

3. A lubricant according to claim 1 in which I the salt is calcium acidphosphate.

4. A lubricant according to claim 1 in which the acid is boric acid.

5; An improved lubricant for metal working processes comprising a thick,pasty, aqueous emulsion of a mineral lubricating oil to which is added asolid filler consisting of a divalent 7. An improved lubricant for metalworking processes comprising an emulsion of 20 to parts of partiallysaponified fat, 35 to 50 parts of mineral oil, 45 to 15 parts of water,and 2 to.

20 parts of a polyvalent metal phosphate.

8. An improved lubricant for metal working processes comprising anemulsion of 20 to 35 parts of partially saponified fat, 35 to 50 partsof mineral oil, 45 to 15 parts of water, and 2 to 20 parts of a salt oflead selected from the group consisting of phosphates, borates andsulfides.

9. An improved lubricant for metal working processes comprising anemulsion of 20 to 35 parts of partially saponified fat, 35 to 50 partsof mineral oil, to 15 parts of water, and 2 to 20 parts of tinphosphate.

10. An improved lubricant for metal working processes, comprising anaqueous emulsion of a mineral lubricating oil to which has been added asa filler a polyvalent metal salt of phosphoric acid, which salt issubstantially insoluble both JOHN C. ZIMMER.

- in oil and water.

